Screening panel securing system

ABSTRACT

A screening assembly  10  includes at least one rail  14  to be secured to a support member of a screening machine. At least one locating formation  16  extends from an operatively upper surface of the rail  14 . Each locating formation  16  includes a catch member  32 . The assembly  10  further includes a plurality of screening modules  12 , each screening module  12  having an end supported on the rail  14 . A pair of modules  12  lie in end-to-end abutting relationship with the abutting ends overlying the rail  14  so that the catch member  32  of each locating formation  16  protrudes beyond an upper surface of the screening modules  12 . Further, a locking member  18  engages the catch member  32  of the locating formation  16  for locking the pair of modules  12  with respect to each other and with respect to the rail  14.

FIELD OF THE INVENTION

This invention relates to screening systems. More particularly, theinvention relates to the securing of screening panels to a screeningmachine.

More specifically, the invention relates to a screening assembly and tocomponents for a screening assembly.

SUMMARY OF THE INVENTION

According to a first aspect of the invention, there is provided ascreening assembly which includes:

at least one rail to be secured, in use, to a support member of ascreening machine to lie intermediate and parallel to side members ofthe screening machine;

at least one locating formation extending from an operatively uppersurface of said at least one rail, the at least one locating formationincluding a catch member;

a plurality of screening modules, each screening module having an endsupported on the at least one rail, a pair of modules lying inend-to-end abutting relationship with the abutting ends overlying the atleast one rail so that at least the catch member of said locatingformation protrudes beyond an upper surface of the screening modules;and

a locking member associated with the at least one locating formation forengaging the catch member of said locating formation for locking thepair of modules with respect to each other and with respect to the rail.

Each rail may be in the form of a length of hollow box-section beam witha longitudinally extending slot defined in an operatively lower face ofthe beam. Thus, the beam may define a channel in which a head of afastening means is slidably received for securing the rail to anunderlying sub-frame of the screening machine. It will be appreciatedthat, with this arrangement, a universal-type rail is provided which canbe used with different types of screening machines where the spacing orpitch between openings for the fastening means differs from machine tomachine.

The beam may have a coating of a plastics material. The plastics coatingmay have a pair of spaced, parallel, longitudinally extending groovesdefined in an operatively upper surface. Each end of each module mayhave a bead extending along an operatively lower surface, the bead, inuse, being received in one of the grooves for effecting lateral locationof the module relative to the rail.

Each locating formation may be in the form of a plate or plate-likestructure which extends upwardly from an operatively upper surface ofthe rail. Each plate-like structure may also be coated with a syntheticplastics material. The plastics material coating the beam and theplate-like structure may be a polyurethane material.

The catch member of each locating formation may be formed in a free endof the plate-like structure.

In one embodiment of the invention, each locating formation may bearranged on its associated rail with longer sides of the plate-likestructure extending parallel to a direction of flow of material over thescreening modules. Instead, in another embodiment of the invention, theplate-like structure of each locating formation may be arranged atsubstantially right angles to a direction of flow of material over thescreening modules. In the latter case, each screening module may have atleast two locating formations associated with each end and a singlelocking member, which has a length substantially the same as that ofeach end of the screening module, may engage both locating formations.

The catch member of each locating formation may be substantiallyhook-shaped. The catch member may be in the form of a hook having adownwardly extending tip for engaging a complementary locking formationof the locking member to effect positive locking of the screeningmodules to the rail. Instead, the catch member may have a substantiallycurved, cam-like shape which engages a similarly curved, but oppositelydirected, cam-like locking formation of the locking member to effectpositive locking of the screening modules to the rail.

The locking member may include a body member which, conveniently, is ofa metal-reinforced plastics material.

In the case of the first embodiment of the invention, where eachlocating formation has a locking member associated with it, an upstreamend (when viewed in a direction of flow of material) of the lockingmember may be rounded to act as a deflector for deflecting the materialto be screened. A slot may open out into a downstream end of the lockingmember into which the catch member of the locating formation is receivedto enable the catch member to engage the complementary locking formationof the locking member. In so doing, positive locking of the screeningmodules to the rails is facilitated.

In the second embodiment of the invention, where the locating formationsare arranged at right angles to the direction of flow of material andone locking member is associated with at least two locating formations,the slots may open out into a side of the locking member so that thelocking member is slid into position relative to the locating formationsin a direction at right angles to the direction of flow of material overthe screening modules.

An operatively lower peripheral edge of each locking member may have aslightly outwardly flared portion which acts as a skirt and bearsagainst upper surfaces of the associated screening modules forinhibiting the ingress of detritus between the bottom of the lockingmember and the upper surfaces of the modules.

Each screening module may be substantially rectangular when viewed inplan and shorter sides of the screening modules may, in use, be arrangedin the direction of flow of material over the screening modules. Theends of the screening modules may thus be the shorter sides of thescreening modules which are received over their associated rails, eachend of each screening module defining a part of at least one recess sothat when the two modules abut end-to-end, at least one completedpassage is formed through which an associated formation passes. Thepassage may be shaped to accommodate its associated locating formationas a snug fit therein.

The modules may be of a synthetic plastics material, suitablyreinforced. Once again, the plastics material from which the modules aremade may be polyurethane. The hardness of the polyurethane used for thelocking member may differ from that of the modules for inhibitingbinding of the locking member relative to its associated modules.Typically, the locking member may be of a harder polyurethane than themodules.

According to a second aspect of the invention, there is provided ascreening module for a screening assembly, the screening moduleincluding:

a body member having a pair of opposed ends;

a part of at least one rectangular recess defined in at least one of theends of the body member, the part of the rectangular recess, in use,mating with a corresponding part of a rectangular recess of a bodymember of an identical module arranged in end-to-end abutment to definea rectangular passage through which a locating formation of thescreening assembly passes; and

a locating means arranged along an operatively lower surface of at leastone of the ends of the body member, the locating means being received ina complementary formation of an underlying rail of the screeningassembly, in use, for locating the module with respect to the rail.

Each end of the body member may be stepped at its lower edge to overliethe rail of the screening assembly. The locating means may be arrangedintermediate an end of the body member and an operatively vertical partof the step.

According to a third aspect of the invention, there is provided anintermediate rail for a screening assembly, the intermediate railincluding:

a hollow, elongate element to be secured to an underlying support memberof a screening machine by a plurality of spaced fasteners, the elongateelement having a longitudinally extending slot defined in a surfacethereof so that heads of the fasteners can be received within theelongate element with shanks of the fasteners protruding through theslots; and

at least one locating formation standing proud of an operatively uppersurface of the elongate element, the, or each, locating formationincluding a catch member.

The elongate element and the at least one locating formation may becovered with a synthetic plastics material.

According to a fourth aspect of the invention, there is provided alocking member for a screening assembly, the locking member including:

a body member having at least one open ended slot defined therein; and

a locking formation arranged in the at least one slot to be engaged, bya catch member of a locating formation of the screening assembly whenthe catch member is received in the slot, in use.

BRIEF DESCRIPTION OF THE DRAWINGS

The invention is now described by way of example with reference to theaccompanying drawings in which:

FIG. 1 shows a schematic plan view of a screening assembly in accordancewith a first example of a first embodiment of the invention;

FIG. 2 shows a schematic end view of the assembly of FIG. 1;

FIG. 3 shows a schematic side view of the assembly of FIG. 1;

FIG. 4 shows, on an enlarged scale, part of a side view of the assemblyof FIG. 1;

FIG. 5 shows a schematic plan view of a screening assembly in accordancewith a second example of the first embodiment of the invention;

FIG. 6 shows a schematic end view of the assembly of FIG. 5;

FIG. 7 shows a schematic side view of the assembly of FIG. 5;

FIG. 8 shows, on an enlarged scale, part of a side view of the assemblyof FIG. 5;

FIG. 9 shows a schematic plan view of a screening assembly in accordancewith a third example of the first embodiment of the invention;

FIG. 10 shows a schematic side view of the assembly of FIG. 9;

FIG. 11 shows a schematic plan view of a screening assembly inaccordance with a fourth example of the first embodiment of theinvention;

FIG. 12 shows a schematic side view of the assembly of FIG. 11;

FIG. 13 shows a schematic plan view of a screening assembly inaccordance with a second embodiment of the invention;

FIG. 14 shows a schematic end view of the assembly of FIG. 13;

FIG. 15 shows a schematic side view of the assembly of FIG. 13; and

FIG. 16 shows, on an enlarged scale, a part of a schematic end view ofthe assembly of FIG. 13.

DETAILED DESCRIPTION OF THE DRAWINGS

In the drawings, reference numeral 10 generally designates a screeningassembly, in accordance with the invention. The assembly 10 comprises aplurality of screening modules 12, a pair of which is shown in FIGS. 1,5, 9, 11 and 13 of the drawings. The pair of modules 12 is shown inabutting end-to-end relationship. It is to be noted in FIGS. 1, 5, 9, 11and 13 that screening apertures of the screening modules 12 are omittedfor the sake of clarity. The screening modules 12 are mounted on asub-frame (not shown) of a screening machine (also not shown). Thesub-frame and the screening machine are well known in the art and arenot described in any detail below.

The modules 12 are secured to the sub-frame of the machine in end-to-endabutting relationship by means of intermediate rails, one of which isshown, for example, at 14 in FIG. 3 of the drawings. The sub-frame ofthe screening machine comprises a plurality of members extending inspaced, parallel relationship between two sides of the screeningmachine. Each member of the sub-frame supports an intermediate rail 14thereon as does each side of the screening machine.

FIGS. 1–4 of the drawings show a first example of a first embodiment ofthe invention. In this example, abutting ends of the modules 12 aresecured to their associated rail 14 by a single locating formation 16and its associated locking member 18.

As illustrated more clearly in FIG. 2 of the drawings, each intermediaterail 14 is formed from a length of hollow box section beam 20 with alongitudinally extending slot 22 formed in an operatively bottom face ofthe beam 20. The beam 20 is covered by a coating 24 of a syntheticplastics material. The beam 20 facilitates securing of the rail 14 toany screening machine as the rail 14 does not have fasteners arranged ata fixed pitch. Instead, a head of a fastener 25 can be inserted into thebeam 20 and is slidable relative to the beam 20 so that the rail 14 canbe mounted on different makes of screening machines thereby improvingthe versatility of the assembly 10.

The plastics coating 24 is, conveniently, a polyurethane material. Oneach side of a longitudinal axis of the rail 14, a groove 26 is formedin the coating 24. A bead or rib 28 at an end of each module 12 isreceived in one of the grooves 26 for locating the module 12 laterallywith respect to the rail 14.

Each locating formation 16 includes a plate-like structure 30 whichstands proud of an upper surface of the rail 14. A catch member 32 isarranged at a free end of the plate-like structure 30. The plate-likestructure 30 is also coated with the coating 24 of polyurethane materialas is the catch member 32.

The locking member 18 includes a metal reinforced plastics body member34. A slot 36 opens out into an operatively downstream end (when viewedin a direction of flow of material to be screened over the modules 12,as illustrated by arrow 38 in FIG. 1 of the drawings) of the body member34. An upstream end 35 of the body member 34 of the locking member 18has a curved shape to act as a deflector for deflecting the material tobe screened away from the locking members 18.

The locking member 18 includes a locking formation 40 which projectsinto the slot 36 and engages the catch member 32 of the locatingformation 16.

In the example of the first embodiment of the screening assembly 10illustrated in FIGS. 1 to 4 of the drawings, the catch member 32 is inthe form of a hook having a downwardly extending tip 42. The lockingformation 40 of the locking member 18 is correspondingly shaped to clipunder the tip 42 of the catch member 32 to effect positive locking ofthe modules 12 relative to the rail 14 in a vertical directionperpendicular to the flow of material.

In the second example of the first embodiment of the screening assemblyillustrated in FIGS. 5 to 8 of the drawings, where, with respect toFIGS. 1 to 4 of the drawings, like reference numerals refer to likeparts, the catch member 32 is of curved profile when viewed side on (asshown in FIGS. 7 and 8 of the drawings) to provide a cam-like lockingsurface 44. This cam-like locking surface 44 of the catch member 32engages a complementary cam-like locking formation 46 of the lockingmember 18 to facilitate positive locking of the modules 12 relative totheir associated rail 14.

In the third example of the first embodiment of the assembly 10illustrated in FIGS. 9 and 10 of the drawings, each pair of abuttingmodules 12 is secured to its associated rail 14 by a pair of locatingformations 16, each with its associated locking member 18.

In the example illustrated in FIGS. 9 and 10 of the drawings, the catchmember 32 of each locating formation 16 has the hook with the downwardlyextending tip 42.

In the example of the invention illustrated in FIGS. 11 and 12 of thedrawings, once again, each pair of modules 12 is secured to itsassociated rail 14 by a pair of locating formations, each with itsassociated locking member 18. In this example, the catch member 32 ofeach locating formation 16 has the curved, cam-like profile with thelocking formation 46 of each locking member 18 having thecomplementarily curved shape.

In all the examples of the first embodiment of the invention illustratedin FIGS. 1 to 12 of the drawings, the plate-like structure of the, oreach, locating formation is arranged so that longer sides of theplate-like structure extend parallel to the direction of flow ofmaterial as illustrated by the arrow 38.

Referring now to FIGS. 13 to 16 of the drawings, a second embodiment ofthe invention is illustrated. Once again, with reference to the previousdrawings, like reference numerals refer to like parts, unless otherwisespecified.

In this embodiment of the invention, the plate-like structure 30 of eachlocating formation 16 is arranged on the intermediate rail 14 withlonger sides of the plate-like structure 30 of each locating formation16 extending at right angles to a direction of flow of material over thescreening modules 12.

It is further to be noted that, in this embodiment of the invention, thepairs of modules 12 are secured to their associated intermediate rail 14by at least two locating formations. However, in contrast to the firstembodiment of the invention described above, use is made of a singlelocking member 18 which has a length approximately the same as that ofthe ends of modules 12 and which engages the two locating formations 16for securing the modules 12 to their associated intermediate rail 14.Thus, a pair of slots 48 open into a side of the body member 34 of thelocking member 18. The locking member 18 is slid into position relativeto the locating formation 16 in a direction at right angles to thedirection of flow of material over the screening modules 12.

It is to be noted that the illustrated embodiment uses locatingformations 16 where the catch member 32 has the curved, cam-likeprofile. It will, however, be readily appreciated that the catch member32 could have the hook-shape as illustrated, for example in FIG. 3 ofthe drawings.

All of the components of the screening assembly 10 are made of ametal-reinforced polyurethane material. However, the hardness of thepolyurethane from which the rails 14, the locating formations 16 and thelocking members 18 are made is harder than the polyurethane from whichthe modules 12 are made so that binding of the modules 12 with respectto the rails 14, locating formations 16 and locking members 18 isinhibited. For example, the modules 12 may be made from a polyurethanehaving a Shore Hardness of 85–93A whereas the polyurethane from whichthe locking members 18, the locating formations 16 and the rails 14 aremade may have a Shore Hardness of 95A or a Shore D-scale Hardness of60–65.

It is an advantage of the invention that a screening assembly 10 isprovided which achieves positive locking of the screening modules 12 totheir associated intermediate rails 14 without the need for anyspecialised tools. In the embodiments illustrated in FIGS. 1 to 12 ofthe drawings, the slot 36 of the locking member 18 is arranged at adownstream end of the locking member 18. As a result, the applicantbelieves that blinding of the slot 36 is unlikely. Even were blinding ofthe slot 36 to occur, merely knocking the locking member 18, from thedownstream end, by means of a hammer, or other similar implement willclear the slot 36 and allow removal of the locking member 18 so that themodules 12 can be removed and replaced. Similarly, with the embodimentillustrated in FIGS. 13 to 16 of the drawings, if the slots 48 wereblinded by material, merely knocking the locking member from the sideinto which the slots 48 open out should facilitate removal of thelocking member 18 to release the screening modules 12 to allow them tobe replaced.

It is a particular advantage of the invention that positive locking ofthe screening modules 12 to the rails 14 is facilitated by means of asystem which does not require any specialised installation tools. Also,the use of the locking members 18 allows rapid removal and replacementof the screening modules 12 thereby reducing down time of the screeningmachine.

It will be appreciated by persons skilled in the art that numerousvariations and/or modifications may be made to the invention as shown inthe specific embodiments without departing from the spirit or scope ofthe invention as broadly described. The present embodiments are,therefore, to be considered in all respects as illustrative and notrestrictive.

1. A screening assembly which includes: at least one rail to be secured,in use, to a support member of a screening machine to lie intermediateand parallel to side members of the screening machine; at least onelocating formation extending from an operatively upper surface of saidat least one rail, the at least one locating formation including a catchmember; a plurality of screening modules, each screening module havingan end supported on the at least one rail with a pair of modules lyingin end-to-end abutting relationship with each other with the abuttingends overlying the at least one rail, at least one recess being definedin the end of the screening module to be supported on the rail, therecess extending between an operatively upper surface and an operativelylower surface of the end of the screening module with the part of therecess of one module being in register with a corresponding part of therecess of the abutting module to define a passage through which thelocating formation passes so that at least the catch member of thelocating formation protrudes beyond the upper surface of the abuttingscreening modules; and a locking member associated with the at least onelocating formation for engaging the catch member of said locatingformation for locking the pair of modules with respect to each other andwith respect to the rail.
 2. The screening assembly according to claim1, in which each rail is in the form of a length of hollow box-sectionbeam with a longitudinally extending slot defined in an operativelylower face of the beam.
 3. The screening assembly according to claim 2,in which the beam has a coating of a plastics material.
 4. The screeningassembly according to claim 3, in which the plastics coating has a pairof spaced, parallel, longitudinally extending grooves defined in anoperatively upper surface.
 5. The screening assembly according to claim4, in which each end of each module has a bead extending along anoperatively lower surface, the bead being received in one of the groovesfor effecting lateral location of the module relative to the rail. 6.The screening assembly according to claim 1, in which each locatingformation is in the form of a plate structure which extends upwardlyfrom an operatively upper surface of the rail.
 7. The screening assemblyaccording to claim 6, in which the catch member of each locatingformation is formed in a free end of the plate structure.
 8. Thescreening assembly according to claim 6, in which each locatingformation is arranged on its associated rail with longer sides of theplate structure extending parallel to a direction of flow of materialover the screening modules.
 9. The screening assembly according to claim8, in which each locating formation has a locking member associated withit and an upstream end of the locking member is rounded to act as adeflector for deflecting any material to be screened.
 10. The screeningassembly according to claim 9, in which a slot opens out into adownstream end of the locking member into which the catch member of thelocating formation is received to enable the catch member to engage thecomplementary locking formation of the locking member.
 11. The screeningassembly according to claim 6, in which the plate structure of eachlocating formation is arranged at substantially right angles to adirection of flow of material over the screening modules.
 12. Thescreening assembly according to claim 11, in which each screening modulehas at least two locating formations associated with each end and asingle locking member, which has a length substantially the same as eachend of the screening module, engages both locating formations.
 13. Thescreening assembly according to claim 11, in which the locatingformations are arranged at right angles to the direction of flow ofmaterial and one locking member is associated with at least two locatingformations, slots opening out into a side of the locking member so thatthe locking member is slid into position relative to the locatingformations in a direction at right angles to the direction of flow ofmaterial over the screening modules.
 14. The screening assemblyaccording to claim 1, in which the catch member of each locatingformation is substantially hook-shaped.
 15. The screening assemblyaccording to claim 14, in which the catch member is in the form of ahook having a downwardly extending tip for engaging a complementarylocking formation of the locking member to effect positive locking ofthe screening modules to the rail.
 16. The screening assembly accordingto claim 1, in which the catch member has a substantially curved shapewhich engages a similarly curved, but oppositely directed, lockingformation of the locking member to effect positive locking of thescreening modules to the rail.
 17. The screening assembly according toclaim 1, in which an operatively lower peripheral edge of each lockingmember has an outwardly flared portion which acts as a skirt and bearsagainst upper surfaces of the associated screening modules forinhibiting the ingress of detritus between the bottom of the lockingmember and the upper surfaces of the modules.
 18. The screening assemblyaccording to claim 1, in which each screening module is substantiallyrectangular when viewed in plan and shorter sides of the screeningmodules are arranged in the direction of flow of material over thescreening modules.
 19. The screening assembly according to claim 1, inwhich the modules and the locking members are of a reinforced syntheticplastics material.
 20. The screening assembly according to claim 19, inwhich the plastics material is polyurethane.
 21. The screening assemblyaccording to claim 20, in which the hardness of the polyurethane usedfor the locking member differs from that of the modules for inhibitingbinding of the locking member relative to its associated modules. 22.The screening assembly according to claim 21, in which the lockingmember is of a harder polyurethane than the modules.
 23. A screeningmodule for a screening assembly, the screening module including: amodule body having a pair of opposed ends; at least one recess definedin at least one of the ends of the module body and extending between anoperatively upper surface and an operatively lower surface of the atleast one end of the module body, the recess, in use, mating with acorresponding part of a recess of a module body of an identical modulearranged in end-to-end abutment to define a passage, arrangedtransversely to a top surface of the body member, through which alocating formation of the screening assembly passes, in use; and aretaining formation arranged along the operatively lower surface of atleast one of the ends of the module body, the retaining formation beingreceived in a complementary formation of an underlying rail of thescreening assembly, in use, for locating the module body with respect tothe rail.
 24. The screening module according to claim 23, in which eachend of the module body is stepped at its lower edge to overlie anassociated rail of the screening assembly.
 25. The screening moduleaccording to claim 24, in which the retaining formation is arrangedintermediate an end of the module body and an operatively vertical partof the step.
 26. An intermediate rail for a screening assembly, theintermediate rail including: a hollow, elongate element to be secured toan underlying support member of a screening machine by a plurality ofspaced fasteners, the elongate element defining a channel runningessentially throughout and having a longitudinally extending slotdefined in an operatively lower surface thereof so that heads of thefasteners can be displaceably received within the channel of theelongate element with shanks of the fasteners protruding through theslot; and at least one locating formation standing proud of anoperatively upper surface of the elongate element, the, or each,locating formation including a catch member.
 27. The intermediate railaccording to claim 26, in which the elongate element and the at leastone locating formation is covered with a synthetic plastics material.28. A locking member for a screening assembly, the locking memberincluding: a body member having at least one open ended slot definedtherein, the at least one slot being defined by a pair of opposed wallsextending operatively upwardly from a bottom of the body member, aspacing between the walls being uniform throughout a height of the slotand the slot opening out into a side of the body member; and a lockingformation arranged in the at least one slot to be engaged by a catchmember of a locating formation of the screening assembly when the catchmember is received in the slot, in use.